Arm rest

ABSTRACT

699,730. Seats. HITTER CO., Inc. Jan. 15, 1953 [May 7, 1952], No. 1243/53. Class 52(ii) A dental &amp;c. chair is provided with arm rests pivotal to a number of in-use positions and an out-of-use position; the pivotal movement comprising clutch surfaces and means being provided for clamping releasably such clutch surfaces. The arm rests, as shown, each comprise an arm surface 55 carried by an arm 53 mounted on an axis from a bracket 37 rigidly secured to the chair. The said axis comprises clutch members 61, 65 and a bolt 67 with a spherical head 69 seated in clutch member 65 and provided with a split nut 73 which may be tightened on the bolt by a screw 75. Contained within and pivoted at 85 to each arm 53 is a lever 83 which has a cam projection 105 coacting with a transverse groove in the face 79 of the nut 73. The lever 83 has at its upper end a handle 91 provided with a notch 99 engageable by a spring 101. Movement of the lever 83 in a clockwise direction by means of the handle 91 against the restraining action of of the spring 101 and notch 99 causes the projection 105 with its engagement with the nut 73 and the bolt 67, to move to separate the clutch members 61, 65 and so permit the arm rest to be moved into an adjusted position such as those shown in dotted lines in Fig. 2.

y 1958 N. E. LAUTERBACH 2,844,193

ARM REST Original Filed May 7, 1952 3 Sheets-Sheet l INVENTOR. NORMAN E LAUTERBAGH HIS ATTKJRNEV July 22, 1958 E. LAUTERBACH 2,844,193

ARM REST Original Filed May 7. 1952 3 Sheets-Sheet 2 INVENTOR. NORMAN E. LAUTERBAGH HIS ATTORNEY y 1958 N. E. LAUTERBACH 2,844,193

ARM REST Original Filed May 7, .1952 3 Sheets-Sheet 3 VII/Ill I INVEN TOR. NORMAN E. LAUTERBAGH HIS ATTORNQY s r 2,844,193 Umted States Patent Othce My 1 2,844,193 ARM REST Norman E. Lauterbach, Pittsford, N. Y., assignor to Ritter Company, Inc., Rochester, N. Y.,a corporation of Delaware I Continuation of abandoned application Serial No.

286,553, May 7, 1952. This application December 26, 1956, Serial No. 630,709

15 Claims. (Cl. 155-198) This invention relates to arm rests for chairs, and more particularly to arm rests for chairs such as employed, for example, in dental, surgical and like practices, one object being to provide an improved arm rest having a more efficient and convenient type of construction and;mode of operation. This is a continuation of my application Serial No. 286,533 filed May 7, 1952, now' abandoned.

Another object is to provide an arm rest which may be readily moved from a position of use to a lowered and out-of-the-way position of non-use.

A further object is to provide an arm rest of the above nature which may be easily locked in any desired position of adjustment between its upper positions of use and its lowered position of non-use.

A further object is to provide an arm rest of the above character in which the release for the locking mechanism is conveniently located on the arm rest for movement therewith so as to be readily accessible to the operator in all. positions of the arm rest.

Still a further object is the provision of a chair having the above advantages in a type of construction requiring a minimum number of parts which may be readily and economically manufactured and assembled.

To these and other ends the invention resides in im- 7 provements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings: V

Fig. 1 is a side elevation of a chair having mounted thereon a pair of arm rests embodying the present invention;

Fig. 2 is a front elevation of the chair showing the arm rests in different adjusted positions;

Fig. 3 is an enlarged side elevation of the arm rest;

Fig. 4 is an enlarged sectional elevation of the arm Fig. 9 is a sectional view substantially along line 9---9 in Fig. 8; and

Fig. 10 is a top elevation of the chair with arm rests turned inward to accommodate a small child.

The preferred embodiment of the invention herein dis- :los ed, by way of illustration, is shown as applied to a lental chair indicated generally at 23 (Fig. 1). As shown In Fig. l, the chair comprises a circular base 25 supporting an electrical motor 27 and a housing 29 for hydraulic nechanism for raising and lowering a seat frame 31 which 7 s mounted on a chair supporting column (not shown) 'otatable with housing 29 relative to base 25, as well under- ;too'd in the art. A lever or pedal 33 is provided below :he seat frame for controlling the tilting movement of said frame relative to the supporting column, as well under- I :tood in the art. Seat frame 31 has a foot-supporting plat- Form 35 fastened thereto adjacent the forward end thereof 1nd has a pair of upwardly extending brackets 37 mounted m opposite sides thereof to which are pivotally mounted 2 a pair of arm rests shown generally at 39, by means hereafter more fully described. A back rest 41 having a head rest 43 pivotally mounted thereon is fastened to a rear bracket 45 on said frame by means of a slide mechanism.

47 and is pivotally connected to brackets 37 at 49 by a means of screws 57 and 59, respectively. The lower portion of arm 53 is formed with an inwardly tapered bore 61 which opens into a portion 63 of the interiorof the arm,

asshown in Fig. 4. Bracket 37 has a cone-shaped clutch member 65 threadedly mounted thereon as shown in Figs.

4 and 5. Clutch member 65 isprefera'bly in the form of V a frustum of a cone having the same angle of inclination as bore 61 formed in arm 53, so that when the arm is in its position as shown in Fig. 4, members 65 and bore 61 mate or clutch together for frictionally holding the arm in adjusted position.

The means for releasably holding arm 53 in adjusted position on member 65 preferably comprises a clamping or radius member 67, Figs. 4 and 5, formed with a curved head 69 adjacent the left end thereof, which rockably seats or fits in a similarly curved seat 71 formed'in the left end of clutch member 65, as shown in Fig. 5. Radius member or bolt 67 passes outwardly through opening63 in the right hand side of arm 53 and is providedwith an abutment or split nut 73 which is adapted to be mounted' f thereon as shown in Figs. 4 and 5. Part or nut 73 is internally threaded to fit bolt 67 and is provided with a clamping screw 75 for drawing the split portions thereof together to securely clamp the nut in the desired position thereof on bolt 67. Nut 73 is provided with a shallow groove 77 formed on the inner surface 79 thereof and extending transversely to split 81, as shown a purpose to be hereafter described.

An elongated, U-shaped clamping member or lever 83 in 7, for

is pivotally mounted within arm 53 at the lower end thereof by a pair of transversely extending cap screws 85 having journal portions 87 on the inner ends thereof which engage a pair of aligned openings or holes 89 formed in the opposite sides of lever 83, as shown in Fig. 6. Lever 83 extends upwardly to a point just below the upper edge of arm 53 and has a handle 91 attached thereto by a pair of rivets 93' (Fig. 8). Handle 91 extends outwardly to the right through an opening 95 at the forward or right hand portion of arm 53 below armsupporting surface 55, as shown in Fig. 8, and is provided with a convenient finger opening 97 adjacent the right end'thereof and a notch 99 adjacent the left end, thereof for releasable engagement with a spring finger 101. Spring 101 is mounted on arm 53 by means of a pair of screws 103 (Fig. 8) and when in engagement with notch 99 holds lever 8.3 in its leftward position which, by means'hereafter described, holds the arm rest in locked position relative to bracket 37.

Lever 83 has a forwardly projecting part or bearing surface 105 (Fig. 5) which engages groove 77 on tle inner surface of nut 73, as shown in Figs. 4 and 5, and when said lever is in its leftward or retracted posi ion shown in- Fig. 4, the center point of part or cam 105 is substantially aligned with the center line of bolt 67. As lever 83 is pivoted on arm 53, cam 105 holds said lever and arm inwardly or to the left of nut 73 (Fig. 4), thereby forcing the wall of bore 61 tightly against clutch member 65. Nut 73 is positioned on bolt 67 sufliciently close to the longitudinal axis of cap screws 85, about which lever 83 pivots, so that as lever 83 moves from'its unlocked position shcwn in Fig. 5 to its locked position shown in Fig. 4, the action of cam 105 forces bore 61 of ar'm153: into -such=tight engagement with clutch member 65'that the arm rest is securely held against rotation on member 65.

In unlockingjhearrn rest for pivotal movementtothe shown in Fig. 4. Not only is the above locking mechadesired position, lever,83.is; swungtothe. right from -its 5 P s t o h n .Fig- .to i v pQsi i ion-s ownin F g. 5,

e eby causingcan; .05. m e .ina c rcular, path: in. a e kw s d r t on. abo t the p talnt r; f ev rir8 r 1. e. th longitudinal axis of screws; 85. "AS; Cami: .5

m y. enga ot h 17, ut- 73. and. o t 67 a e-si arly movedvin a circular path in a clockwise direction aboutv the center. of: curved seat 71 formed in clntch member 65;. a s swin g mo emen ofn t 73. a d b t 7 s. s own:

in Fig. .where-bolt 6,7;is, shown-in its;fully, clockwise,

means. v. t: ille e a as rn 1 5; i ;m v .cl-.. n.a

smallradius, i, e, the.distancefrom-itstip portion to the s u 'n l. xis ofscrews s5, whe easnut 73 is swingingon amuch,l longer. radius. about the center; of curved seat. a d u ved ad 69 f o t 7,;t zm vement; o

lever .83 .tQtheright from itsposition shown in; Fig. 4;, to

its. positionshown in Fig. 5, allowssaid lever'and arrn 53 to move to the right along bolt 67 towards nut 73 and out oftig ht engagement with clutchmernberfiS. Thus, movinglever 83 to its right hand position shown in .Fig.

5 releases clutch bore 61 from clamping engagement, with clutch member 65; thereby allowing arm- 53 to. be pivoted or swungabout member 65 to-desired position, at which point the armrest may be easily locked in; position by merely moving lever 83 to the left to its position shown in Fig. 4. Handle 91 which-is fastened to theupper ;po1

tionof, lever 83 p1'QVides a convenient; means for moving. 1

saidleverfrornlocked-to unlocked positionas shownfin Fig. 3., Lever 83. has an abutment or stop 10'! (Figs, 4 and 5) adjacent the lower end thereof-which engages the inner surface 79-- of nut 73 and limits the leftward-or;

counterclockwise movement of arm 83, as, shown in Fig. 4. Spring, 101, as pointed out above, releasably, holds;

handle 91 andlever 83. in;thei r leftward or retracted-positions as shown in Fig, 8.

It willbe noted in Figs. 1 and 3 that the forward face. :4

ofv bracket. 37 is inclined upwardly toward, t e front;;o f

the chair, and thus the longitudinal axis of clutch mem 1 her 65, about-which arm 53 rotates, is inclineddowm wardly towards the front of the chair,

arm 53 and the axis of member 65,-a generally "triangul shape as shown. Consequently, the front'pQlftlQl'hoffthgr arm rest has a longer radius of rotation than the rear portion thereof, so that When the arm rests are swung nism easy to operate, but as handle 91 and lever 83 are mounted on the arm rest itself, said handle moves with the arm rest, is always in known position relative to the arm rest and is easily accessible'to the operator. Thus the operator can, with one hand, pull handle 91 outward.- ly and swing the arm rest to the desired position and then return said handle to its locking position-shown in Fig. 8.

As the armrest locking-mechanism may be locked in an infinite number of positions, the arm rests-maybe readily locked in any desired adjustableposition, to best period of time.

-It will thus be seen that, the invention accomplishes;

its objects and whileit has been herein. disclosedby reference to the details of a preferred embodiment, it. is to be understood that such disclosure is intendedin an illustrative, ratherthan ail-uniting sense, as it is conmplated that v ri us, modificationsinthe con truction. and-arrangement of thepartswill readilyoccur. to, those: skilled in the art, within the spirit .ofthe inventionand.

the scopeot the a pendedclaims.

I claim- 1 A,cha ir havinga seat frame, an, armrest havingan arm-supporting surface,..1neans supporting, said arm rest for pivotal movement about anaxisinclined upwardly toward the back of said; frame and comprising coacting clutch, surfaces, and clamping means, said clamping,

means .comprisingailever pivotecl onsaid arm rest, a. radius member pivoted,..on said seat frame, and interene. gaging parts-,onsaid lever and member, thepart, onsaid lever having, a shorterhradius. of movement, thanflthe. part on said, seat frame for moving said arm rest and clampingsaid clutch surfaces together, tohold saidiarm.

rest in pivotally adjusted position aboutsaid axis...

2. A chair .hayinga seatframe, an arm rest, means supporting said ar-m ,restfor, pivotal moyementrelative to said frame and comprising coacting clutch surfaces, and.

cl mping members .pivotally snounted on said rest and seat frame, respectively, and provided. with inter: engaging, parts,..one of ,said partshavingalonger radius of movement. than the otherfor actuationby'said other part for, moving. said arm; rest and clamping .sai d clutch. surfaces, together to hold said arm rest in ,pivotall-y ad.-

justed position relative to said, frame.

inwardly beyond their normal substantially, vertical position, the forwardportions ofthe arm restsare moved downwardly and closer togetherthan the rearward-,po r-- Y tions thereof, as well as somewhat rearwardly toward- 3. A chair.having a seat frame, an armrest, meanssaid frame and comprising coactingplutc'h surfaces, and

supporting said arm rest for pivotal movement relative to a clam-ping means, said clampingmeans comprising a leven.

the back of the seat, thereby adapting the; rests to more;

closely support a small patient in; the chainasshown in- Fig. 2. The above differences in radiiof rotation hetween.

the forward and rear end of the arm rest may be easily seen if it is visualized that the longitudinal-axis, o f mern ber 65 and bolt 67 is extended to; the left in Fig. 3. The

above movement o t e m re is ad more-i fie tiveto hold a small child in the chair by slightlycurving; theforward portions of the arm rests towards each other I Thus it will-be seen that the invention provides: anim pivotedon; said anm rest, a radius member pivoted onsaid. fname;. and, int,erengaging,,parts,,on said, lever and member, the part on said lever having:a shorteriradius..

of 'movementthanthepart on said seatframefop-mor:

'ing said arm rest and clamping said clutch surfaces to:

gether ,tohold said arm rest in pivotally,-adjusted;position relative to saidseatrframe.

4; A ..cha ir having, a ,seat frame,;an.-arm. rest, means supporting; said armrest, for pivotahmovement relative to said frame and. comprising coacting, clutch surfaces,

proved arm rest construction in which the armrest may bereadily swung from asubstantially verticalpositiomof use to-a lowered positionof non-use, or-swung inwardly to aid inholding a small patient-in the chair. The leek-.-v ing mechanism is rugged, durable; and highly reliable in operation and may bereleased by merely pulling :handle. 7 91 w r y to move e e 3. o it pos on shown-ins Fig. 5, then the arm rest may be-swung.to the desired. positionof adjustment, at'which point handle 913is pushed inwardly until notch 99 thereofis engaged-,byspring-101,

returning lever- 83 to its'left hand;or-locking;position):

rest,--a radiusmemberpivoted on said frame, andintersaid letter; havinga shorter.radius..ofv movement than the,

P iOB:

clamping. means comprising.alevenpivoted onsaidv arm engaging ;parts on;said lever. and member, the partorn =part-,.O, 1 l eat frame f rm ingsai arm-rest and.

clamping ;sai dflclutc h s urfa;c es together to hold said, arm rest in -pivotally, adjusted, position; relativedo. said seat. frame, and spring means, releasablyengaging. said leverv for releasably lockingsaid clamping--means in clamping,

5. A chair; hayinga seatv frame, an arm rest having,-

an arm supporting surface, means supporting said arm rest for pivotal movement relative to said frame and comprising coacting clutch surfaces, and clamping means, said clamping means comprising a lever pivoted on said arm rest and movable therewith, a radius member pivoted on said frame, and interengaging parts on said lever and member, the part on said lever having a shorter radius of movement than the .part on said seat frame for moving said arm rest and clamping said clutch surfaces together to hold said arm rest in pivotally adjusted position relative to said seat frame, said lever having a handle adjacent said arm supporting surface .for moving said lever relative to said arm rest for clamping and releasing said clutch surfaces.

6. A chair having a seat frame, an arm rest comprising a hollow supporting arm having an arm-supporting surface mounted thereon, means supporting said arm rest for pivotal movement relative to said seat frame and comprising coacting clutch surfaces, and clamping means, said clamping means comprising a lever pivotally mounted within said arm rest, a radius member pivotally mounted on said seat frame, and interengaging parts on said lever and member, said lever having a handle projecting outwardly through an opening in said supporting arm adjacent said arm supporting surface for actuating said lever for moving said arm rest and clamping said clutch surfaces together to hold said arm rest in pivotally adjusted position relative to said frame.

7. A chair having a seat frame, an arm rest comprising a hollow supporting arm having an arm supporting surface mounted thereon, means supporting said am rest for pivotal movement relative to said frame and comprising coacting clutch surfaces, clamping means comprising a lever pivotally mounted within said arm rest, a radius member pivotally mounted on said frame, and interengaging parts on said lever and member, said lever having a handle projecting outwardly through an opening in said supporting arm adjacent said arm supporting surface for actuating said lever for moving said arm rest and clamping said clutch surfaces together to hold said arm rest in pivotally adjusted position relative to said seat frame, and spring means releasably engaging said handle for releasably locking said clamping means in clamping position.

*8. A chair having a seat frame, back rest means pivotally connected with said seat frame for movement between raised and lowered positions, an arm rest on said frame, said arm rest having an arm supporting surface inclined downwardly toward the back of said frame for providing an arm supporting surface of decreasing elevation for the patient as said back rest is lowered relative to the seat frame and arm rest, means supporting said arm rest for pivotal movement about an axis inclined upwardly and rearwardly toward said arm supporting surface and comprising coacting clutch surfaces, and means for releasably clamping said clutch surfaces together to clamp said arm rest in pivotally adjusted position.

9. A chair having a seat frame, back rest means pivotally connected with said seat frame for movement between raised and lowered positions, an arm rest on said seat frame, said arm rest having an arm supporting surface inclined downwardly toward the back of said frame for providing an arm supporting surface of decreasing elevation for the patient as said back rest is lowered relative to the seat frame and arm rest, means supporting said am rest for pivotal movement about an axis inclined upwardly toward the back of said frame and comprising coacting clutch surfaces, and clamping means comprising a lever pivotally mounted on said arm rest for clamping said clutch surfaces together to hold said arm rest in pivotally adjusted position about said axis.

10. A chair comprising, in combination, a frame, a

seat and a back carried by said frame, a pair of arm rests each having a support and each having a forward part and a rearward part, pivot means between each of said supports and said frame, each of said pivot means having an axis about which its support rotates and each of said axes extending upwardly and rearwardly toward the back, said supports with the arm rests carried thereby being swingable about said axes from a normal position in which the supports are approximately vertical to a position in which the supports are directed toward each other, the upward and rearward direction in which said axes extend resulting in a greater amplitude of movement of the forward parts of the arm rests as compared to the rearward parts thereof when the supports are swung toward each other whereby a child seated in said chair is accommodated by the relatively wide spacing of the rearward parts of the arm rests but is restricted in his movement forwardly in the chair by the close spacing of the forward parts of the arm rests and means for releasably locking said supports in a desired position of adjustment. 4

11. A chair in accordance with claim 10 in which the releasable locking means includes clutch parts having an infinite number of locking positions with respect to each other.

12. A chair in accordance with claim 10 in which the locking means includes a hand actuated release element for said locking means carried by each of said supports by which said supports may each both be released and swung with one hand.

13. A chair in accordance with claim 10 in which the back is articulated with respect to the frame and in which the arm rests slope and curve downward and rearward.

14. A chair comprising, in combination, a frame, a seat and a back carried by said frame, a pair of arm rests each having a support and each having a forward part and a rearward part, pivot means between each of said supports and said frame, each of said pivot means having an axis about which its support rotates and each of said axes extending upwardly and rearwardly toward the back, said supports with the arm rests carried thereby being swingable about said axis from a normal position in which the supports are approximately vertical to a position in which the supports are directed toward each other, said pivot means being adjacent the level of the seat whereby the supports are of substantial height and the amplitude of swing of the arms isrelatively large, the upward and rearward direction in which said axes extend resulting in a greater amplitude of movement of the forward parts of the arm rests as compared to the rearward parts thereof when the supports are swtmg toward each other whereby a child seated in said chair is accommodated by the relatively wide spacing of the rearward parts of the arm rests but is restricted in his movement forwardly in the chair by the close spacing of the forward parts of the arm rests and means for releasably locking said supports in a desired position of adjustment.

15. A chair in accordance with claim 14 in which the releasable locking means includes clutch parts having an infinite number of locking positions with respect to each other and in which a clutch release element extends upward within each support, each support having an opening through which a hand actuator for the release element extends whereby each arm and its support may each be both released and swung with one hand.

References Cited in the file of this patent UNITED STATES PATENTS D. 169,473 Burlin er a1. May 5, 1953 877,274 Weber Jan. 21, 1908 1,702,175 Schramm Feb. 12, 1929 1,814,877 Weber July 14, 1931 2,290,672 Cantor July 21, 1942 2,605,648 Sanderlin Aug. 5, 1952 FOREIGN PATENTS 443,063 Germany Aug. 20, 1926 

